code: def test_group_definitions(data, expected):
      grouped = PlotsData(data).group_definitions()
      assert grouped == expected
  
file_path: dvc/tests/unit/render/test_match.py
imports: import pytest
  from funcy import set_in
  from dvc.render import FIELD, FILENAME, REVISION
  from dvc.render.converter.vega import VegaConverter
  from dvc.render.match import PlotsData, _squash_plots_properties, match_defs_renderers
label_desc: Use image node_id 1 for calling a global function with example usage: test_group_definitions(data, expected) without return types